4.1. Therapeutic indications

For the treatment of moderate to severe hypertension as an adjunct to other anti-hypertensive agents.

Due to the complementary mechanism of action the combination of hydralazine with b-blockers and diuretics may enable antihypertensive efficacy at lower dose levels and counteract accompanying hydralazine effects such as reflex tachycardia and oedema.

As supplementary medication for use in combination with long-acting nitrates in moderate to severe chronic congestive cardiac failure in patients in whom optimal doses of conventional therapy have proved insufficient.

4.2. Posology and method of administration

See “Precautions” before use.

Adults:

Hypertension: the dose should be adjusted to the individual requirements of the patient. Treatment should begin with low doses of hydralazine which, depending on the patient's response should be increased stepwise to achieve optimal therapeutic effect whilst keeping unwanted effects to a minimum.

Initially 25 mg bid. This can be increased gradually to a dose not exceeding 200 mg daily. The dose should not be increased beyond 100 mg daily without first checking the patient's acetylator status.

Chronic congestive heart failure: Treatment with hydralazine should always be initiated in hospital, where the patient's individual haemodynamic values can be reliably determined with the help of invasive monitoring. It should then be continued in hospital until the patient has become stabilised on the requisite maintenance dose. Doses vary greatly between individual patients and are generally higher than those used for treating hypertension. After progressive titration (initially 25 mg tid or qid increasing every second day) the maintenance dosage averages 50-75 mg qid.

Paediatric population:

Not recommended

Elderly:

Clinical evidence would indicate that no special dosage regime is necessary.

Advancing age does not affect either blood concentration or systemic clearance.

Renal elimination may however be affected in so far as kidney function diminishes with age.

Method of administration

For Oral use only

The dose of hydralazine should be reduced or the dosage interval prolonged in patients with hepatic or renal impairment.

4.3. Contraindications

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

Idiopathic systemic lupus erythematosus (SLE) and related diseases.

Severe tachycardia and heart failure with a high cardiac output (e.g. in thyrotoxicosis).

Myocardial insufficiency due to mechanical obstruction (e.g. in the presence of aortic or mitral stenosis or constrictive pericarditis).

Isolated right ventricular failure due to pulmonary hypertension.Porphyria.

4.4. Special warnings and precautions for use

Warnings

The overall 'hyperdynamic' state of the circulation induced by hydralazine may accentuate certain clinical conditions. Myocardial stimulation may provoke or aggravate angina pectoris. Patients with suspected or confirmed coronary artery disease should therefore be given Hydralazine Tablets only under cover of beta-blocker or in combination with other suitable sympatholytic agents. It is important that the beta-blocker medication should be commenced a few days before the start of treatment with Hydralazine Tablets.

Patients who have survived a myocardial infarction should not receive Hydralazine Tablets until a post-infarction stabilisation state has been achieved.

Prolonged treatment with hydralazine (i.e. usually for more than 6 months) may provoke a systemic lupus erythematosus (SLE)-like syndrome, especially where doses exceed 100 mg daily. First symptoms are likely to be similar to rheumatoid arthritis (arthralgia, sometimes associated with fever, anaemia, leukopenia, thrombocytopenia and rash) and are reversible after withdrawal of the drug. In its more severe form it resembles acute SLE (similar manifestations as the milder form plus pleurisy, pleural effusions and pericarditis), and in rare cases renal and ocular involvement have been reported. Early detection and a timely diagnosis with appropriate therapy (i.e. treatment discontinuation and possibly long-term treatment with corticosteroids may be required to reverse these changes) are of utmost importance in this life-threatening illness to prevent more severe complications, which may sometimes be fatal.

Since such reactions tend to occur more frequently the higher the dose and the longer its duration, and since they are also more common in slow acetylators, it is recommended that for maintenance therapy the lowest effective dose should be used. If 100 mg daily fails to elicit an adequate clinical effect, the patient's acetylator status should be evaluated. Slow acetylators and women run greater risk of developing the SLE-like syndrome and every effort should therefore be made to keep the dosage below 100 mg daily and a careful watch kept for signs and symptoms suggestive of this syndrome. If such symptoms do develop the drug should be gradually withdrawn.

Rapid acetylators often respond inadequately even to doses of 100 mg daily and therefore the dose can be raised with only a slightly increased risk of an LE like syndrome.

During long term treatment with Hydralazine Tablets it is advisable to determine the antinuclear factors and conduct urine analysis at intervals of approximately 6 months. Microhaematuria and / or proteinuria, in particular together with positive titres of ANF, may be initial signs of immune-complex glomerulonephritis associated with the SLE like syndrome. If overt clinical signs or symptoms develop, the drug should be withdrawn immediately.

Skin rash, febrile reactions and change in blood count occur rarely and drug should be withdrawn. Peripheral neuritis in the form of paraesthesia has been reported, and may respond to pyridoxine administration or drug withdrawal.

Precautions

In patients with renal impairment (creatinine clearance < 30 ml/min or serum creatinine concentrations > 2.5 mg / 100 ml or 221 μmol/l) and in patients with hepatic dysfunction the dose or interval between doses should be adjusted according to clinical response, in order to avoid accumulation of the 'apparent' active substance.

Hydralazine Tablets should be used with caution in patients with coronary artery disease (since it may increase angina) or cerebrovascular disease.

When undergoing surgery, patients treated with Hydralazine Tablets may show a fall in blood pressure, in which case one should not use adrenaline to correct the hypotension, since it enhances the cardiac-accelerating effects of hydralazine.

When initiating therapy in heart failure, particular caution should be exercised and the patient kept under surveillance and/or haemodynamic monitoring for early detection of postural hypotension or tachycardia. Where discontinuation of therapy in heart failure is indicated, Hydralazine Tablets should be withdrawn gradually (except in serious situations, such as SLE-like syndrome or blood dyscrasias) in order to avoid precipitation and/or exacerbation of heart failure.

This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially 'sodium-free'.

4.5. Interaction with other medicinal products and other forms of interaction

Potentiation of effects: Concurrent therapy with other antihypertensives (vasodilators, calcium antagonists, ACE inhibitors, diuretics), anaesthetics, tricyclic antidepressants, major tranquillisers, nitrates or drugs exerting central depressant actions (including alcohol).

Administration of Hydralazine Tablets shortly before or after diazoxide may give rise to marked hypotension.

MAO inhibitors should be used with caution in patients receiving Hydralazine Tablets.

Concurrent administration of Hydralazine Tablets with beta-blockers subject to a strong first pass effect (e.g. propranolol) may increase their bioavailability. Downward adjustment of these drugs may be required when they are given concomitantly with Hydralazine Tablets.

There is potential for the hypotensive effect of hydralazine to be antagonised when used concomitantly with oestrogens or non-steroidal anti-inflammatory drugs.

4.6. Fertility, pregnancy and lactation

Pregnancy

Use of hydralazine in pregnancy, before the third trimester should be avoided but the drug may be employed in later pregnancy if there is no safer alternative or when the disease itself carries serious risks for the mother or child e.g. pre-eclampsia and or eclampsia.

No serious adverse effects in human pregnancy have been reported to date with Hydralazine Tablets, although experience in the third trimester is extensive.

Breast-feeding

Hydralazine passes into breast milk but reports available so far have not shown adverse effects on the infant mothers in whom use of hydralazine is unavoidable may breast feed their infant provided that the infant is observed for possible adverse effects.

Fertility

Not data available.

4.7. Effects on ability to drive and use machines

Hydralazine may impair the patient's reactions especially at the start of the treatment.

The patient should be warned of the hazard when driving or operating machinery.

4.8. Undesirable effects

Some of the adverse effects listed below e.g. tachycardia, palpitations, angina symptoms, flushing, headache, dizziness, nasal congestion and gastro-intestinal disturbances are commonly seen at the start of treatment, especially if the dose is raised quickly. However such effects generally subside in the further course of treatment.

(The following frequency estimates are used: Very common (≥ 1/10), common (≥ 1/100, < 1/10), rare (≥ 1/10000, < 1/1000); isolated cases (< 0.001%).

System Organ Class

Frequency

Adverse effects

Blood and lymphatic system disorders

Rare

Anaemia, leucopenia, neutropenia, thrombocytopenia with or without purpura.

eosinophilia

Isolated cases

Haemolytic anaemia, leucocytosis, lymphadenopathy, pancytopenia, splenomegaly, agranulocytosis

Metabolism and nutrition disorders

Rare

Decreased appetite

Psychiatric disorders

Rare

Agitation, anxiety

Isolated cases

Depression, hallucinations

Nervous system disorders

Very common

Headache

Rare

Dizziness

Isolated cases

Peripheral neuritis, polyneuritis, paraesthesia (these unwanted effects may be reversed by administering pyridoxine).

Eye disorders

Rare

Conjunctivitis, lacrimation increased

Cardiac disorders

Very common

Tachycardia, palpitations

Common

Anginal symptoms

Rare

Oedema, heart failure

Vascular disorder

Common

Flushing, hypotension

Isolated cases

Paradoxical pressor responses

Respiratory, thoracic and mediastinal disorders

Rare

Nasal congestion, Dyspnoea, pleuritic pain

Gastrointestinal disorders

Common

Gastrointestinal disturbances, diarrhoea, nausea, vomiting

Isolated cases

Paralytic ileus.

Hepatobiliary disorders

Rare

Jaundice, hepatomegaly, abnormal liver function sometimes in association with hepatitis.

Skin and subcutaneous tissue disorders

Common

SLE-like syndrome (sometimes resulting in a fatal outcome see section 4.4 Special warnings and precautions for use)

Rare

Hypersensitivity reactions such as pruritus, urticaria, vasculitis, rash

Musculoskeletal and connective tissue disorders

Common

Arthralgia, joint swelling, myalgia

Renal and urinary disorders

Rare

Proteinuria, Blood creatinine increased, haematuria sometimes in association with glomerulonephritis.

Isolated cases

Acute kidney failure, urinary retention.

General disorders and administration site conditions

Rare

Pyrexia, malaise.

Isolated cases

Exophthalmos

Investigations

Rare

Weight decrease

Reporting of suspected adverse reactions:

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit / risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

Signs and symptoms

Symptoms include hypotension, tachycardia, myocardial ischaemia dysrhythmias and coma.

Treatment

Gastric lavage should be instituted as soon as possible. Supportive measures including intravenous fluids are also indicated. If hypotension is present, an attempt should be made to raise the blood pressure without increasing the tachycardia.